XL a COAST AND GEODETIC SURVEY ROBERTS 227 



Mountain and Chickamauga, in the Shenandoah Valley and on Sher- 

 man's march. The naval victory at Port Koyal, possibly of decisive 

 effect on the course of the war, was partly the result of reconnais- 

 sance, piloting, and mine laying by Assistant C. O. Boutelle, Lt. Cdr. 

 C. H. Davis, and others. 



In later wars the diverse skills of the Survey contributed to opera- 

 tions in all theaters. World War II, with its numerous amphibious 

 operations, presented especially difficult requirements for surrepti- 

 tious beachhead surveys, often made at night by Survey officers on 

 military assignment, for the study and prediction of tidal regimes, 

 and for the emergency charting of perilous waters in the little-known 

 island groups. 



Very early in the time of Bache, the slow speeds and unwieldy 

 properties of sailing vessels led to the trial of steamers. The first 

 of these, the Bibb, began work in 184-7, after tests by then Lt. C. H. 

 Davis, who later became a Bear Admiral and Superintendent of the 

 Naval Observatory. His tests of the Bibb signaled the change from 

 sail to steam, perhaps the greatest of the early technological advances 

 in hydrography. 



Major ships of the Survey today displace two or three thousand 

 tons, and they are built to be fairly wide and steady, for much launch 

 handling is necessary for the survey of inshore areas. Speeds are 

 moderate, but the complex of electronic instruments devoted to survey 

 operations is impressive. There are at present four such ships in the 

 Survey fleet, with two more authorized. In addition, tenders of all 

 sizes capable of maintaining themselves at sea are used in intermediate 

 areas too exposed for launches but too close in for major ships. All, 

 ships and launches alike, work with sonic gear permitting rapid and 

 comprehensive scanning of the sea-bottom features. All, moreover, 

 but the launches, are capable of working with radar, shoran, and the 

 Survey's electronic position indicator system, known as EPI. It is 

 hard now to find a quartermaster fully skilled in the ancient art of 

 heaving the lead ! 



The growth of hydrographic work during and after the time of 

 Bache saw continuous improvements and inventions of equipment 

 and methods. Lt. George Stellwagen, operating on Georges Bank, 

 invented a bottom sampler, while Louis Agassiz made studies of 

 Florida coral reef growth especially for the Survey. Lt. Matthew 

 F. Maury, the great oceanographer of the Navy and long Superin- 

 tendent of the Depot of Charts and Instruments, though not officially 

 assigned to the Survey, worked in such close association that he was 

 naturally identified with it. He originated the use of wire in place 

 of hemp for deep-sea soundings, vastly improving accuracy and speed. 

 Registering deep-sea thermometers and water samplers were invented. 



